Now we’re learning more about lightsabers, Obi-Wan’s exile, and Ahsoka Tano (Anakin Skywalker’s padawan from The Clone Wars and Star Wars Rebels) in new novel Ahsoka by E.K. Johnston, which released last week. Screen Rant compiled a list of fifteen things revealed by the novel.

The story reveals how lightsabers get their color. It comes from the kyber crystal, which is used not only in lightsabers but also by the Death Star. These crystals can only be found by a Force user the crystal chooses to make itself visible to, meaning no dark side members can come by the crystals honestly. They have to steal them. When used by somebody on the dark side, the crystals “bleed” — as the novel words it — and can only be seen as the color red. Those not on the dark side can have lightsabers of many other colors, usually green or blue, although we’ve now also seen white (Ahsoka’s dual lightsabers) and purple (because Samuel L. Jackson asked for a purple one with “bad motherf*cker” engraved on it).